Genetic Diversity in a Collection

[Pythonfriend]

By inbreeding, you can concentrate that gene within your population, identify which animals carry the gene, and eliminate them from your population. You then take the healthy surviving animals, continue to breed them to relatives (not necessarily close relatives), and again eliminate those animals carrying the gene. Continue until you have essentially eliminated that deleterious trait, and now you have a healthy line of linebred or inbred animals.

thats most certainly not being done with BPs.

it means that you start breeding different independent lines, for example 5, and inbreed these 5 lines independent from each other. if you get one defect in one of the lines, you scrap the entire line. meaning the parents, the siblings, the grandparents, everything, the whole line is tossed. and you split the best of the remaining lines, so that you again have 5 lines. for this process, inbreeding is maximized. for the first 10 or 20 generations, you dont get any benefits, you will only be splitting and discarding lines. you will come across all kinds of defects and problems, and each of these is dealt with by discarding the entire line. over time, defects and problems will occur less often, and maybe after around 50 generation you have your final product: a highly inbred, highly homozygous, yet relatively healthy line. they all look the same, and one single outbreeding will ruin everything. unless you want to start completely from scratch, the only way to change the genetics of the line without losing it is now genetic engineering.

last time i checked, in BP breeding, people like to add new morphs into their collection. if you want to use inbreeding to "clean" the genome, thats not possible. the first step is to completely seperate your founding stock from the general population of BPs. you could do it, for example, with super pastels. but it takes decades, and all benefits are lost as soon as you breed any of them to anything else. but the only benefit (apart from being useful in genetic engineering and genetic research) is that you have a bunch of super pastels that you can now inbreed without running into random defects and issues.

attempts to do it in order to produce pretty pets are not going well, at least not in the case of dogs:
https://www.youtube.com/watch?v=yZMegQH1SPg

[sorraia]

thats most certainly not being done with BPs.

it means that you start breeding different independent lines, for example 5, and inbreed these 5 lines independent from each other. if you get one defect in one of the lines, you scrap the entire line. meaning the parents, the siblings, the grandparents, everything, the whole line is tossed. and you split the best of the remaining lines, so that you again have 5 lines. for this process, inbreeding is maximized. for the first 10 or 20 generations, you dont get any benefits, you will only be splitting and discarding lines. you will come across all kinds of defects and problems, and each of these is dealt with by discarding the entire line. over time, defects and problems will occur less often, and maybe after around 50 generation you have your final product: a highly inbred, highly homozygous, yet relatively healthy line. they all look the same, and one single outbreeding will ruin everything. unless you want to start completely from scratch, the only way to change the genetics of the line without losing it is now genetic engineering.

last time i checked, in BP breeding, people like to add new morphs into their collection. if you want to use inbreeding to "clean" the genome, thats not possible. the first step is to completely seperate your founding stock from the general population of BPs. you could do it, for example, with super pastels. but it takes decades, and all benefits are lost as soon as you breed any of them to anything else. but the only benefit (apart from being useful in genetic engineering and genetic research) is that you have a bunch of super pastels that you can now inbreed without running into random defects and issues.

attempts to do it in order to produce pretty pets are not going well, at least not in the case of dogs:
https://www.youtube.com/watch?v=yZMegQH1SPg

That's how it works. Whether or not it is being done is irrelevant, that's how it CAN be done and with good purpose.

Right now, from what I have seen, many breeders generally don't even bother to keep track of their animals. Considering this, we really have NO idea how much inbreeding and linebreeding is actually occurring. Also from what I've seen, very little attention is even paid toward health. As long as the animal is the desired morph, and the breeder can get it to eat a few meals, it is considered "healthy" and encouraged to be entered into the breeding population. I could be wrong, but thus far I have not seen any long-term health records for any animals. We can't really say that our animals really are healthy, unless we keep long-term, life long health records over several generations.

As for what is occurring in dogs - One major problem with dogs: Many breeders are NOT actually selecting for healthy, they are selecting for a number of other traits, and maybe half-heartedly selecting health. If a breeder is truly selecting for health, they would not be breeding any animals with a significant health problem. In dogs this would mean not breeding any dogs with hip, knee, elbow, or other joint issues, not breeding any dogs with eye defects, not breeding any dogs with breathing problems or who can't birth normally, not breeding any dogs with skin issues, not breeding any dogs who can't run and play normally, etc. This simply isn't being done. Show breeders are, in general, selecting for those dogs that win in the shows. They are then breeding together those show winners to get more show winners. Over the generations inbreeding occurs, but with so much emphasis on a particular show conformation (which is often actually detrimental to the dog), those dogs are suffering. IF instead of selecting for a show conformation, these breeders were selecting for health, we would start seeing healthier animals who were not plagued with these kinds of health issues. This isn't a problem with inbreeding, this is a problem with the selections that are occurring. It wouldn't matter if those breeders were inbreeding or outcrossing their animals, the only difference is these problems come out faster with inbreeding. They are still going to occur with outcrossing, which is why we now have so many horribly unhealthy mutts, because the breeds they came from were unhealthy to begin with, even though these dogs are now outcrossed. I personally have yet to meet one single mutt who is healthy. Every mutt I have every known, including those belonging to friends and family members, have been unhealthy in one way or another, ranging from skin issues, allergies, temperamental issues, cancers, hip displaysia, knee and elbow issues, eye issues, to generally poor health. It isn't just an inbreeding problem, it really just comes down to POOR SELECTION from the beginning. If you breed unhealthy animals together, you are going to get unhealthy animals, no matter whether or not those animals are related.

[OctagonGecko729]

I keep wanting to jump in but your beating me to it Sorraia. Definitely are codifying my position better then I was.

[OhhWatALoser]

so, you assume that inbreeding can have POSITIVE effects that outweigh the negative consequences, in spite of all the science that says the opposite? heterozygous: one gene can be broken, the individual is still fine. homozygous: either both are broken and you have a dead snake, or both are fine. either you roll two dice, and if you get a one on both, you lose. or you only roll one dice, and the second one is a copy of the first result, and if you get a one, you lose. whats better? No I do not assume anything, I observe. I think it has already been covered how this is false.

and you assume that having only one set of genes can be better than having two different sets of genes? The incorrect use of terminology makes this irrelevant to inbreeding. But if you are saying heterozygous vs homozygous, I say you have a toss up chance depending on many variables, I would never assume anything here either

and you assume that the BP genome is somehow immune against ionizing radiation, carcinogens, and retroviruses? you must assume that if you want to believe that BPs dont have broken genes in their genome. if you accept that the genome of BPs is just as fragile as the genome of any other species, you have to let go of that false assumption. Never even implied anything close to this, all I said is they on average have less genes that causes negative traits then more commonly bred things, like dogs and humans. Yes I am assuming this, based on inbred breedings from all 3 species I have heard about and general knowledge on the human genome

and about the number of generations of inbreeding: it gets worse with each generation. and there is no possible project out there that would require more than one or two generations of inbreeding. so thats where i draw the line, 3 generations of inbreeding is excessive, because you can reach the same goal with less inbreeding. I think it has already been covered, but you are assuming it gets only worse, despite accounts of the opposite.


all the assumptions you make, in order to arrive at the conclusion that inbreeding is perfectly fine no matter what, well, these assumptions contradict a lot of scientific knowledge. i could make a bunch of wild assumptions and then arrive at the conclusion that climate change is actually a good thing. i could make a bunch of wild assumptions to arrive at the conclusion that cigarettes are healthy. Are you serious?

I see no reason to treat an inbred pairing any different. If issues become common, stop breeding that pair, whether they be brother and sister or 50 generations removed.

It is quite simple, pay attention to your pairings, inbred or not. If there are negative traits, you shouldn't even be breeding the first generation, putting a generation number on it just seems silly.

Yup "no matter what," Don't twist things to attempt to make your point

i ignore cases where wildly inbred line-bred BPs are still doing fine, because when determining if smoking cigarettes is healthy or not, i also ignore cases of 105-year-old smokers. 105 year old smokers dont get that old because they smoke, and line-bred BPs that are doing fine are not doing fine because of inbreeding. they are the ones that got lucky, in spite of evidence that the risk of bad things happening is elevated, bad things didnt happen.
Healthy is a very generalized term and how can you really evaluate it? Obviously if an animal is deformed or dies, it's easy to spot. If any animal has a stronger immune system, how can the average ball python breeder know? You brought up the reduction in fertility, do you say that is unhealthy? So why do you ignore the line bred/inbred animals that are producing higher than average, with no other known aliments? Ignoring the volta region ball pythons, is not ignoring a 105 year old, its ignoring an entire inbred country of smokers that live to 105.

My point is inbreeding shouldn't be blindly demonized, it should be done responsibly like ALL pairings. It can have a positive outcome and just so nothing is misunderstood, I said can, not always. I also do not imply I am ignorant of the fact that there can be negatives.

[sorraia]

My point is inbreeding shouldn't be blindly demonized, it should be done responsibly like ALL pairings. It can have a positive outcome and just so nothing is misunderstood, I said can, not always. I also do not imply I am ignorant of the fact that there can be negatives.

I agree entirely.

[sorraia]

To answer the OP's actual question...

I have a couple of questions. The
first is, how do you as keepers typically maintain genetic diversity
in your collection of snakes (assuming that you breed them) or do you
pay attention to it at all? I know inbreeding happens in order to
prove out a new morph, for example breeding an unusual looking baby
back to its parent. Now, if your maintaining a small colony and
holding back a few babies as future breeders in an effort to save
money on new breeders, or if the baby has a gene that's expensive to
acquire by buying a new snake, at some point a lot of the snakes in
your collection will be related to each other. How does this impact
the snakes, or is there any measurable difference in the health of
closely related captive snakes vs their wild brothers and sisters?

For me personally, I am not concerned about inbreeding in terms of "good" or "bad". I think inbreeding is just a tool, which can be used poorly, or can be used well. For me personally, I have only received written pedigrees for 2 of my snakes (distantly related), and a verbal pedigree for 2 other snakes (according to this verbal pedigree, those 2 snakes are half-siblings). For my remaining snakes, I have to make assumptions, and I am assuming that if they come from the same breeder, they are in some way related. I have yet to produce my first clutch, though I did pair my first snakes this year (we'll see!!!). The possibility of inbreeding doesn't bother me. I intend to keep records on my snakes. If I see deleterious traits pop up in a particular pairing, that pairing will not be repeated, and depending on how serious that trait is, I might have serious reconsideration about breeding those two snakes ever again, even to different snakes. If its an extremely serious trait, I may not even breed any of the offspring. But if I have success, then I'll have no qualms against breeding those snakes again, or their offspring, to each other or to different and presumed unrelated snakes. I will keep records on my animals, which would include their health and temperament. I won't know the health of any animals I sell, unless the buyer keeps in touch with me and relates to me what happens to their snake (and keep that snake for life so I never lose track of it - let's face it, that doesn't seem to be what happens in this hobby, it appears that a snake can change hands multiple times throughout it's life), but I will at least know the health of the animals in my personal collection, and with that information I'll be able to make the best informed decisions I can for any future pairings I attempt. (Fortunately I also intend to keep my breeding to a minimum, 1 clutch a year, skipping years as needed to sell offspring, because I simply don't have room for too many snakes. This limited number of clutches per year will make it easier for me to keep such records.)

My second question is this; I have seen
people on this site mention receiving papers with a newly purchased
snake. What do these papers consist of, a pedigree as well as a
feeding chart? How do you guys keep track of the lineage of the
snakes you breed and sell? Or do you keep track of this at all?

For the most part, I've only received feeding charts. Only 2 snakes came with a recorded pedigree. I intend to keep track of lineage, feeding charts, and other important information, which I will supply to any buyers of my snakes.

[Krynn]

That's how it works. Whether or not it is being done is irrelevant, that's how it CAN be done and with good purpose.

It is not irrelevant. Perhaps you missed the topic of discussion, but we are specifically talking about genetic diversity in a collection of snakes.

Now just because there are exceptions to the idea that inbreeding TYPICALLY causes problems in animal populations (in captivity and in the wild), does not mean we should ignore the entire concept of inbreeding depression. We are talking about ball python breeding, and sorraia i'm sure you would at least agree with me that the literature on inbreeding does NOT tell us that reptiles and amphibians can inbreed more then mammals can. Most wild and captive animals suffer a loss of fecundity when they are highly inbred.

The lack of selection in the ball python industry seems to be a problem in itself, but I think that could be an independent thread on its own.

I dont think there is a lot of line breeding in ball pythons, but due to the nature of the market I think it would be terrible if it did happen. Most breeders sell their pythons to other breeders, or hobbiests that plan on breeding. If there were line bred animals, their progeny would quickly suffer from outbreeding depression as soon as someone bred them to another line.

[MonkeyShuttle]

Krynn... I hate you for making me read all that.

[Krynn]

I just wanted to point out, that I think most of us that are arguing are pretty much on the same page. Nobody has said that related snakes should never be paired together because their offspring will have all sorts of defects. I just think that people should be aware of what inbreeding depression is and how it works. That's why I wrote that novel on the first page, but I dont think I did a very good job of explaining it.

BTW sorraia, you clearly understand your genetics and I dont think I have disagreed with any of the science that you have brought up in your posts. I just think that for the most part line breeding is an exception that isnt incredibly relevant for the reptile trade.

Cheers,
-Dylan

[artgecko]

To answer the OP's less-discussed question about records received with snakes from breeders:

Out of the 4 snakes I've purchased thus far, only one came with records (which I was glad to receive. The breeder included a spreadsheet with feeding data, birth date, species / locality, a picture to ID my snake, pictures of each of the parents and the source of those parents (the breeder's lines they were from).

If I breed, I will use a similar record format and note birthdate, sex, morph, parents (with pics and known genetics and breeder source), and feeding / shedding information.

I don't think that you would need a specific symbol / labeling format for snakes until you had quite a few, but have on file (in computer or on paper) the information I listed above for each snake and create new files for hatchlings with the same information.